In the past, most research and development of spatiotemporal data models, those capable
of storing the geographic and temporal aspects of phenomena in the world, has been
focused on tracking current change and planning for the future. Geo-historical information,
that deals with geographic features in the past, introduces several difficult issues that must be
handled to make GIS useful to research and education in history and historical geography:
much, if not most, of the information has uncertain location, time, or attribute values; many
aspects of the information (e,g,, feature creation events, attribute value samples, judgments of
location, uncertainties) need to be precisely documented with sources, descriptions, and
justifications; and ad hoc relationships between features (e.g., parent-child, spatial topology,
temporal topology, region-capital) are frequent. The Geo-Historical Information System is
a rich model designed to store geo-historical information designed to meet these needs. In
initial applications, the GHIS has been used to describe several types of geographic features,
including administrative regions, cities and towns, and the travels of people, and has been
found to be both useful and powerful.